Localized corrosion of equipment is a serious problem in many industries and processes. In particular, corrosion failures in many oil and gas production systems, oil/gas/water transmission pipelines, petrochemical and chemical processing plants, fossil fuel and nuclear power plants are in the form of localized corrosion which may result in loss of production, increase in maintenance cost, environmental pollution and potential health and safety hazards, etc. It is important that the occurrence of localized corrosion is identified and the severity determined in advance of structural failure due to corrosion, particularly catastrophic failure. In addition, the ability of chemicals to inhibit localized corrosion needs to be determined so that they may be effectively implemented in advance of potential corrosive problems.
The problems resulting from localized corrosion have been dealt with for many years with variable success. Localized corrosion is highly stochastic in nature and its occurrence is fairly unpredictable. Thus, it is important that statistical analysis is carried out when studying or monitoring for localized corrosion. Currently, localized corrosion is studied or monitored by measuring directly relatively large features (e.g. pits) on the surface by using standard optical microscopy with limited spatial resolution. Indirect methods are also used, such as electrochemical noise, to characterize localized (e.g. localization index) corrosion.
Further, conventional corrosion evaluation techniques typically require that the testing time extend over weeks or months so that meaningful projections or predictions about corrosion over the course of years may be developed. However, such techniques make it impossible to quickly address new environments and/or materials and develop protocols to address potential corrosion problems. It would thus be desirable of corrosion evaluation methods could be devised to shorten the testing time, yet maintain or increase the accuracy of the results.